Air-pump.



H. M. DUNLAP.

AIR PUMP.

APPLICATION FILED 0cT.17.1916.

Lmfz. Patented Mayzs), 1917.

HARLEY /1/7, .00A/AP HARLEY IVI. DUNLAP, OF BATTLE CREEK, MICHIGAN.

AIR-PUMP.

Specicaton of Letters Patent.

Patented May 29, 191W.

Application le. October 17, 1916. Serial No. 126,130.

To all whom t may concern:

Be it known that I, HARLEY M. DUNLAP, a citizen of the United States, residing at Battle Creek, in the county of Calhoun and State of Michigan, have invented certain new and useful Improvements in A ir- Pumps, of which the following is a specification.

This invention relates to improvements in air pumps. I

The main object of this invention is to provide an improved double acting air pump which is of large/capacity and requires but a relatively small amount of power for its operation.

A further obj ect is to provide an air pump having these advantages which is compact and simple in structure and at the same time not likely to get out of repair.

Further objects, and objects relating to details and economies of construction and operation will definitely appear from the detailed description to follow.

I accomplish the objects of my invention by the devices and means described .in the following specification. The invention is clearly defined and pointed out in the claims.

A structure constituting a preferred embodiment of my invention is illustrated in the accompanying drawings forming a part of this specification, in which:

Figure I is a central vertical section of my improved pump, parts being shown in full lines.

Fig. II is an inverted view. n

Fig. III is a detail perspective view of the rocker arm.

In the drawing, similar characters refer to similar parts throughout. the several views.

Referring to the drawing, I provide a base l having suitable supporting legs. Side by side on this base I mount a pair of low pressure cylinders 2, 2. These cylinders are provided with heads 3 having seats 4 in their upper sides for the high pressure cylinders 5, the heads 3 constituting bases for such cylinders. The high pressure cylinders 5 are provided with heads 6. rIhe cylinders are in the form of tubes open at both ends and are clamped between their respective heads and bases, the cylinders 2 being secured by means of the bolts 7 carriecLby the base 1 and arranged through ears 8 on the heads 3 while the cylinders 5 are clamped rings 18 retained in place by the plates 19,

the structure of the high and low pressure pistons being substantially the same. Ihese pistons or plungers are of the type which admits air above the piston on the downstroke, the packings preventing its return on the up or work stroke.

A rocker arm, designated generally by the numeral 20, is provided with a journal 2l supported in bearings 22 mounted on the under side of the base and centrally between the cylinders. The arms 23 of the rocker arm project upwardly and are bifurcated to receive the links 24 which are connected thereto by the pivots 25 and to the pistons 14 by the pivots 26. These pivots are disposed so that as the pistons approach the end of their up stroke `the pivots connecting the links to the piston and to the rocker arm approach a straight line relative to the aXis of the rocker arm, the rocker arm swinging into the cylinders through the openings 27 in the base, as clearly shown in Fig. I.

The openings inthe heads 3 serve as ports between the high and low pressure pistons and these ports are controlled by the flexible disk valves 28 which are arranged in the seats in the cylinder heads so as to be clamped by the high pressure cylinders, being retained thereby and also serving as gaskets for such cylinders. 'Ihe valves have ports 29 therein and fit the connecting rod so as to serve as glands or gaskets therellVith this simple arrangement of'parts I provide a structure which is of large capacity and may be easily operated, even under considerable pressures. The operating lever 30 is engaged in the socket 3l of the rocker arm journal 2l and .this permits the operator to stand in an upright position to operate the pump. As this lever or handle is oscillated the pistons are alternately operated, and the upstrokes, forcing the air from the low into the high pressure cylinders, discharge the air forced into the high Y pressure cylinders on the previous stroke. 0n the return stroke the air forced into the high pressure cylinder passes above its pisto-n and a new charge of air is taken into the low pressure cylinders.

By arranging the operating mechanism as illustrated and described I secure an action somewhat like a toggle which provides for the greatest power toward the end of the stroke Where the greatest power is required, the travel of the pistons being rapid at the beginning of the stroke and slower toward the end. This construction also results in a pump which develops a large amount of compression with a small amount of power.

AThe structure is compact and may be easily mounted for operation on the running board of an automobile, the base being. provided with feet 32 having perforations 33 adapted to receive screws or bolts when it is desired to permanently mount the pump, or these feet may be engaged by clamps, not illustrated, for temporarily mounting the base.

I have illustrated and described my improvements in an embodiment which I have found very practical. I have not attempted to illustrate or describe certain modifications which I contemplate or which might be desirable under certain conditions, as I believe the disclosure made will enable those skilled in the art to which my invention relates to embody or adapt the same as conditions may require or taste dictate.

Having thus described my invention, what I claim as new and desire to secure by Let- I ters Patent, is:

1. In a structure of the class described, the combination of a base having openings therein, a pair of low pressure cylinders open at their lower ends seated on said base above its said openings, a pair of high pressure cylinders of substantially less diameter than said low pressure cylinders, heads for said low pressure cylinders having seats therein for said high pressure cylinders and constituting bases therefor, heads for said high pressure cylinders having delivery passages therein provided with valves, a coupling pipe connecting said delivery passages at the rear of their valves, one of said passages being provided with a delivery connection, bolts extending from said low pressure cylinder heads to said base and from said high pressure cylinder heads to said low pressure cylinder heads, pairs of high and low pressure cylinder pistons, connecting rods for said pairs of pistons disposed through said low pressure cylinder heads, disk valves for said high pressure cylinders disposed in said seats to surround 2. In a structure of the class described,

the combination of a base having openings thereon, a pair of low pressure cylinders open at their lower ends seated on said base above its said openings, a pair of high pressure cylinders of substantially less diameter than said low pressure cylinders,rheads for said low pressure cylinders having seats therein for said high pressure cylinders and constituting bases therefor, heads for said high pressure cylinders having delivery pas-V sages therein provided with valves, a Coupling pipe connecting said delivery passages at the rear of their valves, one of said passages being provided with a delivery connection, bolts extending from said low pressure cylinder heads to said base and from said high pressure cylinder heads to said low pressure cylinder heads, pairs of high and low pressure cylinder pistons, connecting rods for said pairs of pistons disposed through said low pressure cylinder heads, diskvalves for said high pressure cylinders disposed in said seats to surround said connecting rod and constitute packing glands therefor and packing gaskets for said high pressure cylinder seats, a rocker arm pivioo otally mounted on said base, and links con- Y necting said arms to said low pressure pistons.

3. In a structure of the class described, the combination of a base, a pair 'of low pressure cylinders open at their lower ends mounted on said base, a pair of high pressure cylinders of substantially less diameter than said low pressure cylinders,heads for said low pressure cylinders having seats therein for said high pressure cylinders and constituting bases therefor, heads for said high pressure cylinder having delivery connections, pairs of high and low pressure cylinder pistons, connecting rods for said pairs of pistons disposed through said low pressure cylinder heads, disk valves for said high pressure cylinders disposed in said seats to surround said connecting rod and constitute packing glands therefor and Vpacking gaskets for said high pressure cylnecting said links to said pistons and to said arms being so disposed relative to the axis of the rocker arm that they approach a straight line as the pistons near the ends of their work stroke.

et. In a structure of the class described, the combination of a base, a pair of low pressure cylinders open at their lower ends mounted on said base, a pair of high pressure cylinders of substantially less diameter than said low pressure cylinders, heads for said low pressure cylinders having seats therein for said high pressure cylinders and constituting bases therefor, heads for said high pressure cylinders having delivery connections, pairs of high and low pressure cylinder pistons, connecting rods for said pairs of pistons disposed through said low pressure cylinder heads, valves for said high pressure cylinders disposed in said seats, a rocker arm pivotally mounted on said base, and links connecting said arms to said low pressure pistons, the pivots connecting said links to said pistons and to said arms being so disposed relative to the axis of the rocker arm that they approach a straight line as the pistons near the ends of their work stroke.

5. In a structure of the class described, the combination of a base, a pair of low pressure cylinders open at their lower ends mounted on said base, a pair of high pressure cylinders of substantially less diameter than said low pressure cylinders, heads for said low pressure cylinders having seats therein for said high pressure cylinders and constituting bases therefor, heads for said high pressure cylinders having delivery connections, pairs of high and low pressure cylinder pistons, connecting rods for said pairs of pistons disposed through said low pressure cylinder heads, disk valves for said high pressure cylinders disposed in said seats to surround said connecting rod and constitute packing glands therefor and packing gaskets for said high pressure cylinder seats, a rocker arm pivotally mounted on said base, and links connecting said arms to said low pressure pistons.

6. In a structure of the class described, the combination of a base, a pair of low pressure cylinders open at their lower ends mounted on said base, a pair of high pressure cylinders of substantially less diameter than said low pressure cylinders, heads for said low pressure cylinders and constituting bases for said high pressure cylinders, heads for said high pressure cylinders having delivery connections, pairs oi' high and low pressure cylinder pistons, connecting rods for said pairs of pistons disposed through said low pressure cylinder heads, valves for said high pressure cylinders disposed in said seats, a rocker arm pivotally mounted on said base, and links connecting said arms to said low pressure pistons.

7. In a structure of the class described, the combination of a base, a pair of low pressure cylinders mounted thereon side by side, a pair of high pressure cylinders mounted on said low pressure cylinders in axial alinement therewith, connected pistons for said high and low pressure cylinders, means for delivering air from said low pressure cylinders to said high pressure cylinders, delivery connections for said high pressure cylinders, a rocker arm pivotally mounted on said base centrally between said low pressure cylinders, and links connecting the ends of said rocker arms with the under sides of the low pressure cylinder piston centrally thereof and disposed so that the point of pivotal connection of a link with the rocker arm, and thepivotal point of the rocker arm approach a straight line as the piston nears the upper end of its stroke.

8. In a structure of the class described, the combination of a base, a pair of low pressure cylinders mounted thereon side by side, a pair of high pressure cylinders mounted on said low pressure cylinders in axial alinement therewith, connected pistons for said high and low pressure cylinders, a rocker arm pivotally mounted on said base centrally below said low pressure cylinders, the arms of the rocker arm being adapted to swing into the low pressure cylinders on the compression strokes, links connecting the ends of said rocker arm to the low pressure pistons, means for admitting the compressed air from the low pressure cylinders to the high pressure cylinders, and an outlet connection for the high pressure cylinders.

In witness whereof, I have hereunto set my hand and seal in the presence of two witnesses.

HARLEY M. DUNLAP. [L s] Witnesses:

NAT. BERNARD, H. A. BRIGGs.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

